1. Field of the Invention
This invention relates to a circuit which is directed to image conversion of an input image from imaging means such as an area sensor and a digital image formed by a computer or the like.
More particularly, the present invention relates to a circuit which is directed:
(1) to eliminate noise of a binarized image,
(2) to detect any protrusions or fall-off of an image,
(3) to extract or remove corner portions of the image, and the like.
2. Description of the Prior Art
It has been known in the prior art that an apparatus for dilating/eroding an image by disposing in series conversion stages of a relatively small scale such as 3.times.3 in matrix so that dilation/erosion of an image in a small scale is made at each of the stages and predetermined dilation/ erosion of the image is made through a series of stages as a whole. For instance, U.S. Patent Specification No. 4,395,699 (Stanley R. Sternberg, May 29, 1981) discloses such a conventional dilation/erosion circuit.
In accordance with the conventional dilation/erosion circuit described above, however, it is very complicated to accomplish predetermined dilation/erosion by the combination of dilation/erosion of a small scale such as 3.times.3 and efficiency is extremely low. Furthermore, the combination of small scale dilation/erosion cannot accomplish conversion by dilation/erosion elements having a large radius of curvature. This problem can be solved, in principle, by use of a conversion circuit for effecting dilation/erosion for a large range of N.times.N, but such a circuit becomes great in scale.